基于Protues数字频率计的设计与仿真.pdfVIP

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基于Proteus的数字频率计设计与仿真

摘要：本文主要论述了利用单片机AT89C51进行频率、周期、时间间隔、占空比测量的设计

过程。该频率计采用测量N个信号波形周期的算法，充分利用单片机AT89C51中三个可编程

定时/计数器，结合部分中规模数字电路，克服了基于传统测频原理的频率计的测量精度随

被测信号频率的下降而降低的缺点，实现了频率、周期、时间差、占空比的高精度测量，结

果的显示。该数字频率计的硬件系统电路由前置整形电路、分频电路、基准信号源、单片

机电路和数字显示电路构成。其中单片机电路又由单片机、数据选择器、键盘、状态指示电

路构成。软件系统由主程序、键盘子程序、显示子程序、测量子程序、脉冲高、低电平宽度

测量子程序构成，由汇编语言编写。通过硬件系统和软件系统的相互配合，成功的实现了频

率、周期、时间差、占空比的高精度测量，系统的自校和测量结果的显示。

关键词：数字频率计；周期；单片机

DigitalFrequencyMeasureDesignandSimulationBasedonProteus

Abstract:Thisarticlemainlydiscussesthedesignprocessofusingsingle-chipAT89C51to

measurefrequency,cycle,timeintervalanddutycycle.UsingthealgorithmofmeasuringN

signalcycle,makingfulluseofthethreeprogrammabletimer/counterofsingle-chipAT89C51,

combinedwithsomedigitalcircuits,thefrequencymeterovercomestheshortcomingsofthe

measurementaccuracyreduceswiththereductionofthefrequencyofthemeasuredsignalby

thefrequencymeterbasedontheprincipleoftraditionalmeasurementoffrequency,

achieveshigh-precisionmeasurementsofthefrequency,cycle,timedifferenceanddutycycle,

displaystheresults.Thehardwaresystemcircuitsofthedigitalfrequencymeterismadeupof

thepre-shapingcircuit,sub-frequencycircuit,referencesignalsource,single-chipcircuit,digital

displaycircuitandDCpowersupplyregulatorcircuit.Ofit,thesingle-chipcircuitconsistsof

single-chip,dataselectorandkeyboards.Thesoftwaresystemismadeupofmainprogram,

keyboardsubroutine,displaysubroutine,measurementsubroutine,pulsehighandlowlevel

widthmeasurementsubroutine,preparedbytheassemblylanguage.Throughthecooperationwith

eachotherofthehardwaresystemandsoftwaresystem,thefrequencymetersuccessfully

achieveshigh-precisionmeasurementsoffrequency,cycle,timed